no-promise-in-if.md

Warn if promise is checked for truthiness inside an if condition

It is a common error in Protractor to check if a promise is "truthy" forgetting to actually resolve promise to get a real value. The problem is - promise itself is "truthy" which might make things difficult to spot and debug, or give a false sense of what tests are actually testing.

Rule details

👎 This is an example violation:

var elm = $("#myid");
if (elm.isDisplayed()) {
    // do smth
} else {
    // do smth else
}

The code execution would never reach "do smth else" because elm.isDisplayed() would always be "truthy" no matter if the element is displayed or not.

👍 Instead, one has to explicitly resolve the promise to have a boolean value:

var elm = $("#myid");
elm.isDisplayed().then(function (isDisplayed) {
  if (isDisplayed) {
      // do smth
  } else {
      // do smth else
  }
});

Here is a list of methods currently searched inside if conditions:

• isDisplayed()
• isPresent()
• isElementPresent()
• isSelected()
• isEnabled()